This application targets the recruitment of new investigators o an interdisciplinary program whose focus is the structure and function of neural circuits in health and disease. The Program in Neural Circuits and Behavior (PNCB) will: 1) explore intensively on the biology of neural circuits and the behaviors they produce;and 2) tackle the most important questions in this field using a highly interdisciplinary approach. The PNCB builds on an extraordinarily rich neurosciences community of more than 120 members located at UCSD as well as at the Salk Institute, Scripps Research Institute, and the Burnham Institute. The PNCB is a recent joint creation of the School of Medicine, through the Department of Neurosciences, and the Division of Biological Sciences, through the Section on Neurobiology. The Chairs of the Section (Anirvan Ghosh) and the Department (William Mobley) have committed energy and resources to what they view as the most important next step for the neurosciences -" to decipher the structure and function neural circuits in the normal brain and in brains affected by neurological disorders". PNCB existing members are Robert Malinow, Jeffrey Isaacson and Massimo Scanziani. All occupy space in the CMG building;the new recruits would also be located there to enhance all aspects of career development. One of the new recruits would develop and use new optogenetic tools for imaging function. The other would examine circuit function in mouse models, including models of disease. Thus, they would bring new technologies and concepts to UCSD while benefitting immensely from a nurturing neuroscience community. The PNCB will also include about 20 additional members of the greater community whose work is in neural circuits at levels of analysis ranging from genes to higher order behaviors. By establishing close links between PNCB members and clinicians and scientists in the greater UCSD campus (e.g. Chemistry, Pharmaceutical Chemistry, Physics, and Psychology), this new program will undoubtedly foster many new insights into the biology of neural circuits. Indeed, it is our expectation that our recruits and their colleagues will transform our understanding of the organization and function of neural circuits.